package pta.MOOC.ch01.ex03;

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner reader =new Scanner(System.in);
        double r;  //球的半径
        while(reader.hasNext())
        {
            r=reader.nextDouble();
            System.out.printf("%.3f\n",volumn(r));
        }
    }
    public static double volumn(double r)
    {
        return 4.0/3.0*3.1415926*r*r*r;
    }
}